As many of you will have already seen, we were in for a surprise this morning. Soon after first light, the Manton Bay female – Maya as we are now calling her – stood up to reveal a newly-laid egg in the nest.
This came a quite a surprise; we weren’t expecting an egg until next week. So what’s going on? Having read up on the biology of egg-laying, fertilisation normally occurs 24 hours prior to the egg being laid. 28(10) and Maya have been copulating regularly since Sunday – more than enough time for the egg to have been fertilised. What is more surprising is that eggs have developed in the female’s ovary. Normally it is the arrival of the male and the first copulations that trigger this. In this case, however, it would seem that simply being back at the nest where she has reaered young each summer since 2010 was enough for Maya to get into breeding mode; and thus trigger the development of eggs. Last year she laid the first egg 20 days after arriving and this year it has taken 23 days. Here’s our first view of the egg this morning.
Our only worry now is that 28(10) has no experience of incubating. He’s going to have to learn the ropes very quickly, but the fact that he is breeding with an experienced female will certainly help. We’ll have another update later in the day.